This is a proposal from the Children's Hospital of Philadelphia (CHOP) to become part of the Pediatric Quality Measures Program's (PQMP's) Centers of Excellence (CoE) network. CHOP has formed an organizational architecture for a new CoE that builds on a strong, existing infrastructure already in place including investigators with breadth and depth in leadership and methodological expertise in quality and outcome assessment, unique data resources, and strategic partnerships. The CoE will include five methodological cores: (1) Quality Informatics-using the tools of informatics to adapt quality metrics to the electronic health record (EHR); (2) Multivariate Matching Laboratory--The lab will provide a unique analytic strength that will augment traditional analytic approaches to create scientifically rigorous pediatric risk adjustment models, produce better assessment of health and healthcare disparities, and improve validation of new quality measures; (3) Hospital Metrics-development of measures that focus on inpatient quality; (4) Medical Home-measurement of the performance of the medical home and community services that connect to it; and, (5) Health Plans-a special emphasis on measurement of plan enrollment duration and stability. The proposal has 6 specific aims: (1) Form the organizational architecture for a new CHOP CoE devoted to advancing the science of quality measurement and participating effectively in the PQMP; (2) Enhance a core measure of pediatric healthcare quality-avoidance of inappropriate use of antimicrobial therapy for otitis media with effusion-by adapting it for electronic health records; (3) Develop and validate pediatric readmission outcome measures including a traditional readmission measure based on information obtained on admission and a new readmission measure based on information collected at discharge, with the intent of assessing outpatient care related to readmissions; (4) Develop and validate the duration and stability of child health insurance coverage measures; (5) Enhance the developmental screening core measure by adapting it for EHRs and linking screening data from primary care to receipt of community-based early intervention services; and, (6) Develop a Multivariate Matching Lab and apply matching methods to risk adjustment, disparity assessment, and metric validation. The CHOP CoE will collaborate with several children's hospitals in the Pediatric EHR Data Sharing Network (PEDSNet) and the GE Healthcare Medical Quality Improvement Consortium multi-practice data warehouse of over 15 million electronic health records. Stakeholder alliances with State Medicaid Directors, Independence Blue Cross of Pennsylvania, clinicians, families, and others, will provide substantive input on the applicability and importance of all proposed metrics. In summary, with the expertise, data, infrastructure, and alliances that are necessary to be successful, the CHOP CoE proposal is highly responsive to the requirements of the U18 RFA-HS-11-001 and should provide unique value to the PQMP.